1. Field of the Invention
The present invention relates to apparatus for agitating a fluid containing a sludge-like material, such as liquid manure, and in particular, it relates to portable agitators for agitating the sludge-like material into a slurry.
2. Description of the Prior Art
The storing of liquid manure in feed lot, hog and dairy operations has become relatively common. The manure is generally collected in either a concrete pit located outside or underneath a building, or in an earthen-type pond. The manure is stored for either later use on fields or to be hauled away and disposed of otherwise.
The manure is substantially in a fluid form that contains solids that eventually settle out onto the bottom of the pit or enclosure. In order to remove the manure from the pit or enclosure in an efficient and easy manner, the liquid portion of the manure and the solids are agitated to form a slurry. The slurry can then be easily pumped out, removing both liquid and solid matter, from the pit or enclosure.
The Graham U.S. Pat. No. 4,329,069 illustrates the use of a device that is inserted through a section of piping into a pit containing a liquid manure so as to mix the solids and the liquid to form a slurry. A hydraulic motor is positioned near the top of the tube and has a relatively long drive shaft extending down the tube with blades positioned along the drive shaft. The arrangement in the Graham Patent has the disadvantage that debris could become entangled within the tube along the blades. Moreover, the long drive shaft of Graham is apt to vibrate in use.
The Bellows et al U.S. Pat. No. 3,168,255 illustrates a liquid manure agitator having a propeller attached at the end of a long shaft that extends into the manure pit. In using the agitator of the Bellows Patent, there is the danger that the propeller can be damaged by hitting against the sides or the floor of the pit. Moreover, it is very hard to hold the agitator in a desired position.
The Conover U.S. Pat. No. 3,235,232 shows an agitator that is placed vertically into a pit. The agitator has a motor up at the top of the unit and a long drive shaft with two sets of propeller blades positioned in a tube. The device of the Conover Patent is designed for use in a drainage-type ditch where fluid flows past the agitator and is not particularly suited for use in a still-type pond or pit where the agitation needs to be directed in order to form a suitable slurry.
The Stencil Manufacturing Company of Denmark, Wis., markets a liquid manure agitator under the mark "THE SLUDGE MOVER I". The Stencil Manufacturing device includes a long shaft with a pivotally-attached lower portion on which the hydraulic motor and propeller are attached. The device is suspended from a draw bar on the tractor. A linkage assembly is included that is operable from the end of the shaft extending out of the pit so that the agitation can be directed within the pit. However, the propeller is movable to direct the agitation of the manure only along a plane of the shaft of the device.